1. Field of the Invention
The present invention relates to a connector for piping for connecting hoses which are employed to transfer a fluid such as gasoline, oil, water, air and the like.
2. Description of the Prior Art
As disclosed in Japanese Unexamined Utility Model Publication (KOKAI) No. 41794/1989 and illustrated in FIG. 5, a fitting for piping for connecting hoses has been known so far. The fitting for piping comprises a cylinder-shaped fitting body 300, annular seal members 500 disposed on an inner peripheral surface of the fitting body 300 and on an outer peripheral surface of a pipe 400 disposed in the fitting body 300, a retainer member 600 disposed in the fitting body 300 and assembled on an outer peripheral surface of the pipe 400 thereby retaining the seal members 500 and the pipe 400 in the fitting body 300.
The retainer member 600 is made of a flexible material. The retainer member 600 includes a tubular body 661 having an inner diameter substantially equal to an outer diameter of the pipe 400, the tubular portion 661 which includes an annular groove 661a disposed at a rear end having an inner diameter being greater than the inner diameter of the tubular body 661, and a plurality of leg portions 662 extending from a rear end of the tubular portion 661, bent outwardly and including a concaved groove 662a formed on an outer peripheral surface.
The retainer member 600 is inserted into the fitting body 300 at the tubular portion 661 thereof. The annular groove 661a of the retainer member 600 engages with an annular convexed portion 400a formed on an outer peripheral surface of the pipe 400, and the concaved groove 662a of the retainer member 600 engages with an annular flanged portion 300a formed on an inner peripheral surface of the fitting body 300 at a rear end, thereby holding the pipe 400 in the fitting body 300 and holding the seal members 500 with a front end of the tubular portion 661 by way of a bushing 700.
When the above-mentioned conventional fitting for piping is installed in a piping system and used actually, the pipe 400 is pressed in a direction coming out of the hose fitting body 300, the thus pressed pipe 400 is held by the leg portions 662 disposed between the annular groove 661a and the concaved groove 662a. Accordingly, the leg portions 662 are subjected to a flexural stress. Since the retainer member 600 is made of a flexible material, it is deformed and there arises rickety engagement between the fitting body 300 and the pipe 400. Further, when the fitting body 300 and the pipe 400 are subjected to an external force working in a direction being perpendicular to their axes, the leg portions 662 are again subjected to a flexural stress. Likewise, there arises rickety engagement between the fitting body 300 and the pipe 400.
In addition, since the concaved groove 662a of the leg portions 662 engages with the annular flanged portion 300a of the fitting body 300 at a rear, the rear end of the leg portions 662 protrudes from the rear end of the fitting body 300. As a result, when something is accidentally brought into contact with the protruding rear end of the leg portions 662, there is a fear for disengaging the above-mentioned engagement. Thus, the conventional fitting for piping might damage the reliability of a total piping system.